1. Field of the Invention
This invention relates to vacuum electric furnaces and more particularly to apparatus for advancing the work pieces in the furnace.
2. Description of the Prior Art
Various provisions have heretofore been made for advancing work pieces within a vacuum electric furnace.
It has heretofore been proposed, for use in furnaces, to employ conveying apparatus of the walking beam type having the beams thereof exposed within the furnace made of refractory material and with provisions for cooling. The structures heretofore provided for that purpose were, however, unsuited for vacuum electric furnaces operating at temperatures in excess of 2200.degree. F. and were not adequately resistant if such temperatures were employed and were subject to dimensional instability. An example of such walking beams is illustrated at pages 270 to 273, inclusive, of Industrial Furnaces, 4th Edition, Vol II, by W. Trinks and M. H. Mawhinney, published 1967, by John Wiley and Sons, Inc., New York, N.Y.
The work pieces may be in a hostile environment with temperatures at levels at which most metals, other than refractory metals, are unstable thereby rendering the work piece advancing structure dimensionally unstable.